(verb) An expression one makes when someone makes a comment or does something contrary to what you believe is acceptable. This expression has been made popular by Toni Braxton's sister, "Tamar Braxton," on the reality tv show, "Braxton Family Values." --

It's another way of saying, "knock it off," or "Cut it out," and can be short for an expression such as, "Get your life together, because you're obviously going insane if you believe that"

Toni: Tamar, that's why I can't go anywhere with you because you're always acting a fool.